nal discovery regarding potentially sovereign alter ego co-defendant without further im- pinging that defendant’s immunity) (quot- ing Arriba Ltd. v. Petroleos Mexicanos, 962 F.2d 528, 534 (th Cir.1992) (“At the very least, discovery should be ordered circumspectly and only to verify allega- tions of specific facts c

Court is hesitant to do unnecessarily. See First City, Texas—Houston, N.A. v. Rafidain Bank, 150 F.3d 172, 176 (2d Cir.1998); see also Arriba Ltd. v. Petroleos Mexicanos, 962 F.2d 528, 534 (Sth Cir.1992) (recommending that “discovery should be ordered circumspectly and only to verify allegations of specific facts cruc